A new complexity metric for FH/SS sequences using fuzzy entropy.

This paper presents a new complexity metric to evaluate the unpredictability of a frequency-hopping/spread-spectrum (FH/SS) sequence based on fuzzy entropy (FuzzyEn). According to the property of the FS/SS sequence, the definition of a fuzzy membership function for a complexity metric is presented and a basic theorem for FuzzyEn complexity is proved. Simulation and analytical results show that the proposed FuzzyEn works and can effectively discern the changing complexities of the FH/SS sequences, which are compared with a complexity metric based on approximate entropy (ApEn). The FuzzyEn scheme has obvious advantages in robustness to resolution parameters and sensitivity to vector dimensions. [ABSTRACT FROM AUTHOR]